The Cold War (1947-1991) describes decades of political hostility between the United States and the Soviet Union. The conflict was defined as "cold" because neither the U.S. nor the USSR (Union of Soviet Socialist Republics) officially declared war against the other. However, several pivotal moments nearly pushed the two nations — and subsequently, the world — to nuclear war. Take a look at a Cold War timeline that details the key conflicts and events of the mid-20th century.
Toward the end of World War II in 1945, Germany found itself facing the Allied forces of the world, including both the U.S. and the USSR. Despite ideological differences between the democratic nation and the communist Soviet Union, their leaders had a singular focus: to stop Adolf Hitler in his quest for world domination.
- USSR Declared War on Germany (December 6, 1941) - After Hitler broke the Molotov-Ribbentrop Pact between the USSR and Germany by invading Poland (part of the USSR) in June 1941, the Soviets declared war on Germany.
- Yalta Conference (February 4-11, 1945) - American president Franklin D. Roosevelt, British Prime Minister Winston Churchill and Soviet Premier Joseph Stalin joined to make plans for postwar Europe, including the partitioning of Germany and Berlin.
- V-E Day (May 8, 1945) - Eight days after Hitler committed suicide, Germany surrendered to the Russian army, ending World War II in Europe. The day was celebrated as V-E (Victory in Europe) Day.
- V-J Day (August 14, 1945) - (August 14, 1945) - Japan surrendered to Allied forces on August 14, 1945, after the U.S. dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on August 6 and 8.
- Potsdam Conference (July 17-August 2, 1945) - World leaders divided Germany and Berlin into four Occupation Zones each; the zones in the west would be controlled by Britain, France and the United States, and the eastern zone would be controlled by the Soviet Union.
It didn't take long after Hitler's defeat for conflict to arise between the USSR and the other Allied powers in redistributed Germany. In his 1946 "Sinews of Peace" speech, Winston Churchill named the Joseph Stalin-led Soviet presence as "an iron curtain" across Europe. Britain, France and especially America's discomfort with the potential spread of Soviet communism was matched by the USSR's disdain for Western capitalism.
- The Truman Doctrine (March 12, 1945) - U.S. president Harry Truman pledged to provide aid to democratic nations fighting the spread of communism.
- The Marshall Plan (June 5, 1945) - Secretary of State George C. Marshall proposed the Marshall Plan, which would provide economic assistance to European countries after World War II.
- The Berlin Blockade (June 24, 1948-May 12, 1949) - The USSR attempted to stop Western influence and access into East Berlin by blocking the roads, railways and canals leading to East Berlin. The Western powers resorted to airlifting supplies (known as the Berlin Airlift) to the trapped East Berlin citizens until the blockade was lifted in 1949.
- Korean War Began (June 25, 1950) - Seventy-five thousand soldiers from Soviet-aided North Korea invaded Western-aligned South Korea. Two days later, President Truman sent U.S. troops into the war to defend South Korea against the communist invasion, and the People's Republic of China sent forces in October.
- Death of Joseph Stalin (March 5, 1953) - Soviet Premier Joseph Stalin died at the age of 74. Nikita Khrushchev took control of the USSR as the First Secretary of the Communist Party. He reversed many of Stalin's policies and directed Soviet focus to the space program.
- Korean War Ended (July 27, 1953) - North Korea, South Korea, the People's Republic of China, and the U.S. signed the Korean Armistice Agreement in 1953. It established the Korean Demilitarized Zone between North and South Korea and ended the Korean War.
- The Warsaw Pact (May 14, 1955) - The Soviet Union and seven Soviet satellite states formed the Warsaw Pact as a defense treaty in response to the integration of West Germany into NATO (North Atlantic Treaty Organization) earlier in the year.
- Vietnam War Began (November 1, 1955) - After the failure of the Geneva Accords (which established elections to unify North and South Vietnam), the U.S. established the American Military Advisory Group to support South Vietnam, unofficially entering the conflict.
- Suez Canal Crisis (October 29, 1956) - Soviet-backed Egyptian president Gamal Abdel Nasser nationalized the valuable Suez Canal, causing Israel, France and Britain to send forces into Egypt. Britain and France withdrew their forces after the U.S. threatened economic sanctions if the crisis did not de-escalate.
- The Space Race Began (October 4, 1957) - The Soviet Union sent Sputnik I, the first artificial satellite, into space. It sent Sputnik II and Laika the dog — the first living creature in space — a month later on November 1, 1957.
- U.S. Established NASA (July 29, 1958) - The United States responded to both Sputnik missions by forming the National Aeronautics and Space Administration (NASA) in 1958.
The 1960s brought an increased amount of suspicion on both sides of the Cold War. The tension came to a head during the Cuban Missile Crisis, as nuclear war seemed possible and even imminent for 13 full days. Changes in leadership forced both nations to reexamine their national priorities and to focus on their ideological values.
- U.S. U-2 Spy Plane Shot Down (May 1, 1960) - Soviet forces shot down a U.S. spy plane over the Soviet Union and captured its pilot. Peace talks failed when the Soviets proved that the U.S. was conducting espionage; two years later, they exchanged the pilot for a Soviet spy in American custody.
- First Man in Space (April 12, 1961) - Soviet cosmonaut Yuri Alekseyevich Gagarin became the first human to travel in space, as well as the first person to orbit the planet.
- Bay of Pigs Invasion (April 17, 1961) - The CIA attempted to invade Cuba in order to remove communist leader Fidel Castro. The invasion failed, bringing international embarrassment to the United States and tighter tension with the USSR.
- Berlin Wall Went Up (August 13, 1961) - Communist East Germany constructed the Berlin Wall, also known as the Antifascistischer Schutzwall ("antifascist bulwark") to protect and insulate its citizens from the democratic influence of West Germany.
- Cuban Missile Crisis (October 14-28, 1962) - After discovering secret Soviet missile bases in Cuba, the U.S. weighed a response that would not lead to nuclear war. The situation eventually de-escalated with the Soviets removing their Cuban missiles in exchange for the U.S. removing their missiles in Turkey.
- John F. Kennedy Assassinated (November 22, 1963) - President John F. Kennedy was assassinated in Dallas, Texas by Lee Harvey Oswald, a former Marine and Soviet sympathizer.
- Gulf of Tonkin Incident (August 2-4, 1964) - Two American destroyers reported that they were attacked by North Vietnam, leading the U.S. to increase its military presence in Vietnam.
- Brezhnev Replaced Krushchev (October 15, 1964) - Leonid Brezhnev was selected as Chairman of the Presidium of the Supreme Soviet after Khrushchev was removed from power.
- U.S. Deployed into Vietnam (March 8, 1965) - The U.S. sent its first combat troops to defend the American airbase at Da Nang.
- Invasion of Czechoslovakia (August 20, 1968) - Troops from four Warsaw Pact countries invaded Czechoslovakia in order to stop the reforms of leader Alexander Dubček's Prague Spring reforms. Dubček was arrested by the Komitet Gosudarstvennoy Bezopasnosti (KGB) and forced to resign.
- Apollo 8 (December 21-27, 1968) - The U.S. successfully sent a manned spacecraft to orbit the moon.
- Apollo 11 (July 20, 1969) - American astronauts landed on the moon, effectively winning the Space Race against the Soviet Union (who later abandoned their lunar programs).
- Strategic Arms Limitation Treaty (May 26, 1972) - The U.S. and the Soviets negotiated the first of several treaties (SALT I) that regulated arms in both countries.
- Paris Peace Accords (January 27, 1973) - North Vietnam, South Vietnam, Viet Cong, the United States, and other countries involved in the war signed a peace treaty that ended American involvement in the Vietnam War and attempted to stop hostility between North and South Korea.
With the end of the Vietnam War and the Space Race, much of the tension between the United States and the Soviet Union had begun to ease. Though there would be several concerning events between the United States and the Soviets, the last part of the 20th century found leaders of both countries making a concerted effort toward peace and collaboration.
- The Fall of Saigon (April 30, 1975) - The Vietnam War officially ended when Saigon, the capital of South Vietnam, fell to the People's Army of Vietnam from the north. Saigon was renamed Hồ Chí Minh City, and Vietnam was reunified as the Socialist Republic of Vietnam.
- Apollo-Soyuz Test Project (July 15, 1975) - The U.S. and the Soviet Union launched the first crewed international space mission, their first spaceflight collaboration.
- Iranian Hostage Crisis (November 4, 1979-January 20, 1981) - As a response to the U.S. granting asylum to Shah Pahlavi, Iranian militants held 52 American citizens hostage at the U.S. embassy in Tehrān after the Iranian Revolution.
- USSR Invaded Afghanistan (December 24, 1979) - The Soviet Union sent troops into Afghanistan to install Soviet-backed Babrak Karmal as President of Afghanistan. The event instigated the Soviet-Afghan War, which would last ten years.
- U.S. Boycotted 1980 Olympics (March 21, 1980) - The United States announced that it would boycott the 1980 Moscow Olympic Games as a protest of the Soviet invasion of Afghanistan in 1979. An additional 65 nations followed their lead, while 80 countries sent athletes to compete in the games.
- USSR Boycotted 1984 Olympics (May 9, 1984) - Fourteen Eastern Bloc countries, including the Soviet Union, East Germany and Vietnam, boycotted the 1984 Los Angeles Olympic Games. The nations cited "anti-Soviet hysteria" in the United States, but many assumed that the boycott was retaliation for the U.S.-led Olympic boycott in 1980.
- Gorbachev Took Power (March 11, 1985) - Mikhail Gorbachev became the final leader of the Soviet Union when he was elected as General Secretary in 1985. His policies of glasnost ("openness") and perestroika ("restructuring") set the stage for the last years of Soviet power.
- Chernobyl Disaster (April 26, 1986) - An explosion at the Chernobyl Nuclear Power Plant in Ukraine tested the strength of the struggling USSR. The Soviet response to the disaster only invited more international attention, and Gorbachev himself admitted that Chernobyl was a direct cause of the fall of the Soviet Union.
- Poland Became Democratic (August 24, 1989) - Tadeusz Mazowiecki took office as Poland's first non-communist prime minister since the Cold War began. Poland then became the first democratic nation in the Eastern Bloc (followed by Hungary months later).
- Fall of the Berlin Wall (November 9, 1989) - Massive protests in East Berlin prompted the East German government and the Soviet Union to open the border between East and West Berlin. That evening, both East and West Berliners tore down the wall and freely passed through the checkpoints in celebration.
- Malta Summit (December 2-3, 1989) - President George H.W. Bush and General Secretary Gorbachev met to discuss the end of the Cold War, signaling an easing of international tension.
- Reunification of Germany (October 3, 1990) - East and West Germany were officially reunited as the nation of Germany.
- End of the Soviet Union (December 26, 1991) - Most Soviet republics had already withdrawn from the Soviet Union when Mikhail Gorbachev resigned his post on December 25. The next day, the USSR ceased to exist, and Boris Yeltsin, president of Russia, now presided over an independent state.
The four decades of the Cold War had many dramatic twists and turns, as well as international incidents. Take a look at a visual Cold War timeline that shows how one pivotal event quickly led to another.
Although the Cold War did eventually have an end date, it was not due to masterful negotiations or international friendship. The collapse of the Soviet Union would impact Europe for decades — and the relationship between the United States and Russia would continue its uneasy legacy for years to come. For more information on the U.S. involvement in foreign wars and relationships, check out a timeline of American wars since the American Revolution.